All the more reason to ensure the Parking Brake operates properly.
Whenever I rent a truck (not often) I always rent from Ryder. Much better maintained equipment.
The OPP (Ontario Provincial Police) here have been puling the plates off U-Haul trucks left and right for quite some time for failures to pass random inspections.
I recently moved from Wisconsin to Texas and used the same size truck and trailer combo… I can not stress enough!!! SLOW!!! At 60 m.p.h. the trailer started to sway and created a loop of wobble that was hard to control. If this happens pump your breaks a few times to disrupt the rhythm. Also keep plenty of distance between you and the car in front of you and get ready for people to cut you off… I also want to stress that driving this set up is more physically demanding than driving a car or pick up.